JP5291609B2 - Piping support structure - Google Patents

Abstract

A piping support structure which can improve the earthquake-proof performance of an existing piping system without modifying the system. A piping support structure (30) comprises a support frame which is provided with: supports (1) raised from the mounting surface and disposed at an interval in the radial direction of piping (20) and at an interval in the axial direction of the piping (20); beams (2) supported by the supports (1) in the radial direction; beams (3) supported by the supports (1) in the axial direction; first earthquake damping-mechanisms provided to first structural planes (4) each configured of a beam (2) and of supports (1) which are adjacent to each other in the radial direction; and second earthquake-damping mechanisms provided to second structural planes (5) each configured of a beam (3) and of supports (1) which are adjacent to each other in the axial direction. The piping support structure (30) also comprises the piping (20) which is supported at support points on the beams (2).

Description

  The present invention relates to a structure that supports piping installed in various plants such as a nuclear power plant, a thermal power plant, and a chemical plant.

As shown in FIG. 15, the pipes installed in various plants are restrained (fixed) at all the support points 102 in the support frame 101 in the direction perpendicular to the axis of the pipe 100 (X direction). (Y direction) is fixed at a part of the support point 102 in consideration of the thermal expansion of the pipe 100, but is movable at the remaining support points 102.
In addition, the piping 100 is stretched in the plant, and when the piping 100 is arranged in a different direction, a plurality of supporting frames 101 are used as shown in FIG. Support with.

  When the above pipe support structure is subjected to a large vibration due to a large earthquake, the damping performance of the entire support structure including the support frame 101 is small. Therefore, it is necessary to prepare for damage to the pipe fixing part and damage to the pipe body. is there. Further, when a large deformation occurs in the entire pipe support structure, a means for preventing collision with an adjacent plant building or the like is necessary. Further, when a plurality of support frames 101 are used, the relative displacement between adjacent support frames 101 prevents the piping 100 from being damaged between the support points 102, and the support points 102 themselves. It is necessary to prevent damage. For example, when the relative displacement Δx occurs as shown in FIG. 16, the pipe may be damaged at the part (a) between the pipe fixing points and the part at the pipe fixing point (A).

Therefore, in order to improve the seismic performance of piping, in Patent Document 1, a laminated rubber body is inserted between the piping and the supporting frame to improve the damping performance of the piping system, thereby reducing the response of the piping during an earthquake. Propose to let you.
Patent Document 2 proposes that the vibration suppression device absorbs vibration energy during an earthquake and reduces the response of the piping by connecting the vibration suppression device fixed to the support frame and the piping with a rod. .

JP-A-63-312594 JP-A-1-188735

However, in the case of a structure that directly supports a pipe as shown in FIGS. 14 and 15 with a support frame, there may be no space for incorporating a device such as a laminated rubber body between the pipe 100 and the support frame 101. Therefore, in the case of an existing support frame, the pipe system needs to be greatly modified.
This invention is made | formed based on such a subject, and even if it is an existing thing, it aims at providing the piping support structure which can improve seismic performance, without performing piping system repair.

The pipe support structure of the present invention made for this purpose is provided with a vibration control mechanism in a structure composed of columns and beams, or columns and girders, without repairing the piping system, The gist of the invention is to provide a pipe support structure capable of improving seismic performance. That is, the pipe support structure of the present invention is erected from the installation surface, arranged with a gap in the radial direction of the pipe, and a plurality of struts repeatedly arranged with a gap in the axial direction of the pipe, It is comprised from the support frame provided with the beam supported by a support | pillar along radial direction, the girder supported by a support | pillar along an axial direction, and piping supported by the support point on a beam. The pipe support structure of the present invention includes a first seismic control mechanism provided on one or two or more first construction surfaces composed of struts and beams adjacent in the radial direction, struts and girders adjacent in the axial direction. And a second vibration control mechanism provided on one or two or more second structural surfaces , each of which includes at least two or more continuous pipe support structures. The characteristic is tuned .

  In the pipe support structure of the present invention, the first vibration control mechanism is provided on the first structural surface including a beam having a support point at which the pipe is restrained from moving in the radial direction (hereinafter also referred to as a restraint support point). It is preferred that In the pipe support structure of the present invention, it is preferable that the second vibration control mechanism is provided on the second structural surface adjacent to the beam having a support point at which the pipe is restrained from moving in the axial direction. A reaction force is greatly applied to the restraint support point when a large vibration is applied to the pipe support structure. Therefore, in order to increase the damping performance around the restraint support point, a vibration control mechanism is provided on the first construction surface including the beam having the restraint support point and / or the second construction surface adjacent to the beam having the restraint support point. It is recommended to provide it.

A damper member can be used as the first damping mechanism or the second damping mechanism of the present invention. By providing the damper member in the composition surface, the damping performance of the composition surface can be improved. As the damper member, known members such as a shaft yield type damper, a shear panel type damper, and a friction type damper can be used.
As the first vibration control mechanism of the present invention, in addition to the damper member, a configuration in which the beam is provided with a cross-sectional reduction portion whose characteristics are set in consideration of the influence of the pipe vertical load on both sides in the radial direction with the support point as the center. Can be. In this configuration, the bending energy is generated by bending and yielding the cross-section reducing portion due to the bending moment generated at both ends of the beam by the vibration.

  In the pipe support structure of the present invention, it is preferable to include a transition control mechanism that regulates the displacement of one or both of the radial direction and the axial direction of the support frame. By restricting the displacement of the support frame, the pipe support structure is prevented from colliding with an adjacent structure. Moreover, the damage of the piping between support points and the damage prevention effect of the piping at a support point are ensured.

  Since the piping support structure of the present invention is provided with a vibration control mechanism on the construction surface, even if it is an existing structure, it is possible to improve the seismic performance without repairing the piping system.

It is a figure which shows the basic composition of the piping support structure in 1st Embodiment. It is a figure which shows the damping mechanism used for the piping support structure in 1st Embodiment, (a) shows schematic structure of an axial yield type damper, and its load-displacement history curve, (b) is a shear panel type damper. The schematic structure and its load-displacement history curve are shown, (c) shows the schematic structure of the friction damper and its load-displacement history curve. An example is shown in which a notch is provided in the beam to improve the damping performance. The piping support structure in 2nd Embodiment is shown. It is a figure explaining the detail of the transition control mechanism of FIG. It is a figure which shows the transition control mechanism which controls the displacement of a vibration direction. It is a figure which shows the example which provided the displacement control mechanism in the support frame itself to which the shaft yield type damper was applied. It is a figure which shows the example which provided the displacement control mechanism in the support frame itself which applied the shear type damper (or friction type damper). It is a figure which shows the example which provided the displacement control mechanism in the support frame itself to which the friction type damper was applied. (A) shows the example of the piping support structure to which 3rd Embodiment is applied, (b) shows the structure of the support frame. It is a figure which shows the dominant mode (dotted line) of the X direction of the support frame shown in FIG.10 (b). It is a figure which shows the dominant mode (dotted line) of the Y direction of the support frame shown in FIG.10 (b). The state where the loads P1-P7 of the Y direction acted on the support point of the piping support structure shown to Fig.10 (a) is shown. It is a figure which shows setting the load pa (Nay) and pb (Nby) which generate | occur | produce with the damping devices a and b in the load state of FIG. 13 as a yield load. It is a figure which shows the basic composition of the conventional piping support structure. It is a figure which shows the conventional piping support structure which supports orthogonal piping.

<First Embodiment>
Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
As shown in FIG. 1, the pipe support structure 30 according to the first embodiment includes a support frame 10 and a pipe 20 supported by the support frame 10.

The support frame 10 is configured as follows.
A plurality of support columns 1 standing from the installation surface G are provided. The struts 1 are arranged in two rows at intervals in the radial direction of the pipe 20 (X direction in the figure), and are arranged in five rows at equal intervals in the axial direction of the pipe 20 (Y direction in the figure). The In addition, although the piping support structure 30 is extended in an axial direction, FIG. 1 has shown only the part.

The pipe support structure 30 includes a beam 2 supported by the column 1 along the radial direction of the pipe 20 and a beam 3 supported by the column 1 along the axial direction of the pipe 20. The first structural surface 4 is constituted by each unit composed of two struts 1 and beams 2 adjacent to each other in the radial direction of the pipe 20. Further, the second structural surface 5 is configured by each unit from the two columns 1 and the girders 3 adjacent to each other in the axial direction of the pipe 20.
A brace 6 is provided on each of the first composition surface 4 and the second composition surface 5. The brace 6 is disposed in an inverted V shape on each first construction surface 4 and each second construction surface 5 to improve the rigidity of the support frame 10. In the present embodiment, the brace 6 is a constituent element of a vibration control mechanism provided on each first structural surface 4 and each second structural surface 5.

  In the support frame 10 configured as described above, the pipe 20 is supported in the vertical direction at the support point P on the beam 2. Further, the pipe 20 is fixed at each support point P so that its radial movement is restricted. Furthermore, the pipe 20 is fixed so that the movement in the axial direction is restrained at the support point P (the support point P in the middle in the axial direction) where the ends of the arrows abut each other. The reason why the number of support points P restrained in the axial direction is small is to suppress the influence of thermal stress generated in the pipe 20 due to thermal elongation.

  In the support frame 10 that directly supports the pipe 20, for example, when large vibration energy is generated due to an earthquake, a large reaction force is generated at the support point P and in the vicinity thereof. Therefore, the pipe support structure 30 is provided with a first vibration control mechanism on the first structural surface 4 including the beam 2 having the support point P at which the pipe 20 is restrained from moving in the radial direction. In addition, the pipe support structure 30 is adjacent to the beam 2 having the support point P where the axial movement of the pipe 20 is restricted, that is, on the two second structural surfaces 5 that are continuous in the axial direction across the beam 2. The second seismic control mechanism is provided. In FIG. 1, the brace 6 drawn by a thick line indicates that the first vibration control mechanism is provided on the first structural surface 4.

As the first damping mechanism and the second damping mechanism, various damping devices can be used. An example is shown in FIG. 2, and the present invention includes a shaft yield damper 11 (FIG. 2A), a shear panel damper 12 (FIG. 2B), and a friction damper 13 (FIG. 2C). It can be applied as a first vibration control mechanism and a second vibration control mechanism. However, the present invention is not limited to this, and other vibration control devices that exhibit a damping effect can be applied. Since the supporting frame 10 that supports the pipe 20 often bears a small load, it is appropriate to use the friction damper 13 that easily realizes non-linear behavior under a small load. Since the shaft yield type damper 11, the shear panel type damper 12, and the friction type damper 13 are known to those skilled in the art, the description thereof is omitted here.
The damping device such as the axial yield type damper 11 has a non-linear load-displacement relationship due to the input load accompanying large vibration energy such as a large earthquake (yield of the steel, friction type in the case of the axial yield type damper and the shear panel type damper). In the case of a damper, adjust it so that it enters the sliding area). By doing so, in the event of a large earthquake, the load-displacement relationship of the damping device is entered, and the seismic energy is absorbed by the history energy.

  It is possible to improve the damping performance of the support frame 10 in addition to providing the vibration control device as described above. For example, as shown in FIG. 3A, by providing notches (cross-sectionally reduced portions) 14 on the beams 2 on both sides in the radial direction of the pipe 20 (omitted in FIG. 3) with the support point P as the center. The damping performance of the structural surface can be improved. In this vibration control mechanism, the notch 14 is bent and yielded by a bending moment (indicated by arrows) generated at both ends of the beam 2 due to vibration, and the load-displacement history energy (FIG. 3B) Absorb energy. However, the beam 2 needs to secure a strength capable of supporting a vertical load by the pipe 20.

  In the present embodiment, the first structural surface 4 and the second structural surface 5 that are not related to the fixed support point P are provided with the braces 6 in the present embodiment. It may be removed. If it is the brace 6 that supports only the vertical load, it may be changed to a column member so as not to affect the deformation in the horizontal direction. Moreover, the support conditions of the piping 20 may be the same as the conventional one.

  As described above, according to the present embodiment, the first structural surface 4 and the second structural surface 5 are provided with the vibration control mechanisms (the first vibration control mechanism and the second vibration control mechanism). In the piping support structure 30 as well, it is not necessary to repair the piping system. Further, by incorporating a vibration control mechanism only on the structural surface 4 and the structural surface 5 related to the fixed support point P of the pipe 20, the damping effect of the support frame 10 can be improved more efficiently, and at the same time the pipe is fixed. Costs can be reduced because repairs to structures other than the vicinity of points (removal of braces, etc.) are unnecessary. In particular, as shown in FIG. 3, when notches are provided in the beam 2, there is no need to replace the existing braces 6 provided on the first structural surface 4 and the second structural surface 5 with seismic devices. This is advantageous in terms of cost.

Second Embodiment
Next, a displacement control mechanism for controlling the displacement of the support frame 10 of the first embodiment will be described with reference to FIGS.
As shown in FIGS. 4 and 5, the first example of the displacement control mechanism is to restrict the displacement of the support frame 10 using the adjacent structure 15, and the support frame 10 (girder 3) and the adjacent structure 15. A stopper 16 is provided between the two. The stopper 16 includes a concave female member 16a and a convex male member 16b. Both the female member 16a and the male member 16b are made of steel. The female member 16a is installed in the adjacent structure 15 parallel to the direction in which the displacement is to be controlled, and the male member 16b is installed in the support frame 10 (girder 3). In addition, it cannot be overemphasized that the male member 16b may be provided in the adjacent structure 15, and the female member 16a may be provided in the support frame 10. FIG.
As shown in FIG. 5B, the gap Δ between the female member 16a and the male member 16b is set so that the maximum displacement amount of the support frame 10 is within the allowable displacement amount. By providing this stopper 16, the characteristics of the frame (support frame 10) shown in FIG. 5C and the characteristics of the stopper 16 are added, and the support frame 10 is moved to the right side of FIG. 5C until the allowable displacement is reached. The behavior of the diagram is shown.

Next, as shown in FIG. 6, the displacement control mechanism of the second example is a stopper 17 using an elastic body such as rubber, and the adjacent structure 15 orthogonal to the direction (vibration direction) in which the displacement is to be controlled. A stopper 17 made of an elastic body is installed on the side surface.
The stopper 17 is installed so as to contact the support frame 10 or to provide a gap amount Δ (FIG. 6B) between the stopper 17 and the support frame 10. In any case, the stopper 17 is installed so that the maximum displacement amount of the support frame 10 is within the allowable displacement amount. By providing this stopper 17, the characteristics of the frame (support frame 10) and the characteristics of the stopper 17 shown in FIG. 6C are added, and the support frame 10 is moved to the right side of FIG. 6C until the allowable displacement is reached. The behavior of the diagram is shown.

The displacement control mechanism can also be installed on the support frame 10 itself without the adjacent structure 15. This example will be described with reference to FIGS.
FIG. 7 shows a support frame 10 to which the axial yield type damper 11 is applied. In this case, a pair of stoppers 18 are provided in a C shape on both sides of the first structural surface 4 with the support point of the shaft yielding damper 10 interposed therebetween. As shown in FIG. 7A, the stopper 18 has one end fixed to the beam 2 and the other end provided with a gap between the column 1 and the stopper 18. This gap defines the allowable displacement amount of the support frame 10.
According to the support frame 10 described above, as shown in FIG. 7B, when a rightward load indicated by a white arrow is applied to the beam 2 due to an earthquake, the upper limit of the support frame 10 is set to the maximum amount of displacement rightward. Transforms into However, when the amount of displacement reaches the allowable amount of displacement, the tip of the stopper 18 located on the right side hits the column 1 and the displacement of the support frame 10 is controlled.

FIG. 8 shows a support frame 10 to which a shear panel type damper 12 is applied. In this case, a pair of stoppers 19 are provided on both sides of the shear plane type damper 12 in the first structural surface 4. As shown in FIG. 8A, the stopper 19 has one end fixed to the beam 2 so that a gap is provided between the stopper 19 and the shear panel type damper 12. This gap defines the allowable displacement amount of the support frame 10.
According to the above support frame 10, as shown in FIG. 8 (b), when a rightward load indicated by a hollow arrow is applied to the beam 2 due to an earthquake, the upper limit of the support frame 10 becomes the maximum amount of displacement rightward. Transforms into Along with this, the shear panel type damper 12 is deformed into a parallelogram. However, when the displacement amount of the support frame 10 reaches the allowable displacement amount, the lower left corner of the shear panel damper 12 hits the stopper 19 located on the left side, and the displacement of the support frame 10 is controlled.
Although the shear panel type damper 12 has been described here, the same applies to the friction type damper 13.

Next, for the friction damper 13, a displacement control mechanism can be provided on the support frame 10 itself without using a stopper. This third example is shown in FIG.
The friction damper 13 includes a first friction body 131 and a second friction body 132. The friction damper 13 absorbs vibration energy by the frictional force of the contact surface between the first friction body 131 and the second friction body 132. One end side of the brace 6 is fixed to the second friction body 132, and the second friction body 132 is displaced integrally with the brace 6.
The first friction body 131 includes a high μ portion 131a and a low μ portion 131b, and the high μ portions 131a are disposed on both sides of the low μ portion 131b. The high μ portion 131a has a higher coefficient of friction than the low μ portion 131b. Of course, the level of the friction coefficient is the friction coefficient of the contact surface between the first friction body 131 and the second friction body 132. Further, the friction coefficient of the contact surface of the second friction body 132 is equal.

  In the range where the low μ portion 131b of the first friction body 131 and the second friction body 132 are in contact with each other, the friction damper 13 described above has a low friction force F1 as shown in FIG. The first friction body 131 and the second friction body 132 are relatively displaced. However, when the second friction body 132 comes into contact with the high μ portion 131a of the first friction body 131 as shown in FIG. 9B, the first friction body as shown in FIG. 9C. Since a high frictional force F2 is generated between 131 and the second friction body 132, the displacement of the second friction body 132 is restricted.

As described above, by providing the displacement control mechanism in the first embodiment, it is possible to keep the displacement of the support frame 10 within an allowable range while realizing efficient seismic energy absorption. Therefore, it is possible to avoid the displacement and the support frame 10 or the pipe 20 from being damaged.
In the case of the steel stopper 16 of the first example, when the support frame 10 tries to displace beyond the gap amount Δ between the female member 16a and the male member 16b in the event of an earthquake, the female member 16a and the male member 16b come into contact with each other and are supported. The rigidity of the stopper 16 is added to the rigidity of the frame 10 to prevent the displacement of the support frame 10 from exceeding the allowable displacement.
In the case of the stopper 17 made of an elastic body of the second example, when the support frame 10 comes into contact with the stopper 17 at the time of an earthquake, the stopper 17 does not progress further when deformed to some extent as shown in FIG. The displacement amount of the support frame 10 is controlled to be equal to or less than the allowable displacement amount using the property.
As in the third example, when the displacement control mechanism is installed in the support frame 10 itself, there is an advantage that the displacement of the support frame 10 can be controlled within an allowable range regardless of surrounding structures.

<Third Embodiment>
It is preferable to synchronize the vibration characteristics of the support frame 10 as a whole in order to ensure the earthquake resistance of the support frame 10. Therefore, it is necessary to adjust the characteristics of each vibration control mechanism (vibration control device) used. In the third embodiment, an example will be described.

For example, the example which adjusts the characteristic of a damping device about piping support structure 30 provided with piping 20 supported by two frames A and B shown in Drawing 10 (a) is explained.
<Rigidity adjustment>
i) The rigidity of the vibration control device is adjusted so that the dominant modes in the X direction and the Y direction in both the frames A and B become vibration modes in which the frame moves in the same direction as a whole.
For example, when the frame A is a support frame as shown in FIG. 10B, the dominant modes in the X direction and the Y direction are as shown in FIGS. 11 and 12, respectively.
ii) The rigidity is adjusted so that the dominant mode frequencies in the respective directions of the frames A and B coincide. Specifically, assuming that the natural frequencies of the dominant mode in the X direction and the Y direction of the frame A are Tax and Tay, and the natural frequencies of the X direction in the frame B and the dominant mode in the Y direction are Tbx and Tby, Tax = Tbx. , Tay = Tby.

<Adjustment of yield load>
The load acting on the support point P of the pipe 20 at the time of an earthquake differs for each support point P due to variations in inertial force. Therefore, since the load acting on the vibration control device also varies, the yield load of each vibration control device is set in consideration of them, and the vibration is synchronized even after the vibration control device yields.
For example, as shown in FIG. 13, when loads P1 to P7 in the Y direction are applied to the support point where the pipe 20 is fixed in the Y direction due to an earthquake, they differ depending on variations in inertial force. Here, when adjusting the yield axial force of the vibration control device so as to yield in the load state of FIG. 13, the load generated in the vibration control device in this state is set as the yield axial force. That is, taking the vibration control devices a and b as examples, the loads pa (Nay) and pb (Nby) generated in the state of FIG. 13 are set as the yield loads. FIG. 14 visually shows this characteristic. That is, the vibration control devices a and b simultaneously yield at the shaft.

As described above, by synchronizing the vibration characteristics of the support frame 10 as a whole, the seismic energy can be efficiently absorbed by the pipe support structure 30 as a whole.
Further, in order to synchronize the vibration characteristics of the support frames 10, the support frame 10 vibrates in the same phase, and the pipe 20 between the fixed points (support points) P is damaged due to relative displacement between the support frames 10. It is possible to prevent the fixing point (support point) P from being damaged.

  The above description is only one embodiment of the present invention, and the configuration described in the above embodiment can be selected and changed to other configurations as appropriate without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Supporting frame 1 ... Post, 2 ... Beam, 3 ... Girder, 4 ... 1st structural surface, 5 ... 2nd structural surface 6 ... Brace (1st damping mechanism, 2nd damping mechanism)
DESCRIPTION OF SYMBOLS 11 ... Shaft yield type damper, 12 ... Shear panel type damper, 13 ... Friction type damper 14 ... Notch part, 15 ... Adjacent structure, 16, 17, 18, 19 ... Stopper 20 ... Pipe 30 ... Pipe support structure

Claims (6)

Standing up from the installation surface, arranged with an interval in the radial direction of the pipe, and a plurality of struts repeatedly arranged with an interval in the axial direction of the pipe,
A beam supported by the column along the radial direction;
A girder supported by the column along the axial direction;
A first seismic control mechanism provided on one or two or more first structural surfaces composed of the struts and the beams adjacent in the radial direction;
A support structure comprising: a second vibration control mechanism provided on one or two or more second structural surfaces composed of the struts adjacent to the axial direction and the girders;
The pipe supported at a support point on the beam;
A pipe support structure comprising:
When at least two or more of the pipe support structures are continuous, their vibration characteristics are tuned . The first vibration control mechanism is
The pipe support structure according to claim 1, wherein the pipe support structure is provided on the first structural surface including the beam having the support point where the radial movement of the pipe is restricted. The second vibration control mechanism is
The pipe support structure according to claim 1 or 2, wherein the pipe is provided on the second structural surface adjacent to the beam having the support point where the axial movement is restricted.   The piping support structure according to any one of claims 1 to 3, wherein the first damping mechanism or the second damping mechanism is a damper member. The first seismic control mechanism is a cross-section decreasing portion whose characteristics are set in consideration of the influence of a vertical pipe load provided on the beam on both sides in the radial direction around the support point. The piping support structure according to any one of 3.   The piping support structure according to any one of claims 1 to 5, further comprising a transition control mechanism that regulates displacement of one or both of the radial direction and the axial direction of the support frame.

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